The Glorious Independence of Luxembourg

OP: Luxembourg has been around since before 1890, but that was the year where they gained a lot more independence. Previously, the Grand Duchy (it's the world's only such monarchy) of Luxembourg had been in a personal union under the Netherlands, where the Dutch king also served as the Luxembourgish grand duke. But then, in 1890, the Dutch ended up with a queen instead (Wilhelmina, who would be succeeded by two more queens, leading to an uninterrupted 123-year-long female rule of the Netherlands). Some weird "Salic" laws that applied only in Luxembourg said that a woman could not be a Grand Duchess, so they had to scramble to find a different monarch for their country (i.e. one with a penis) and the connection with the Netherlands was severely weakened. So there you go, it's a country that gained independence thanks to sexism. (They made up for it later with not one but two Grand Duchesses, Marie-Adelaide and Charlotte.)